Dynamic stabilization system

ABSTRACT

A spinal stabilization system including an insert positionable in the channel of the housing of a vertebral anchor, and an associated support construct including a spacer and at least one cord extending through the insert. In some instances the construct includes first and second cords extending through first and second bores of the insert. A clamping member clamps the cord(s) in the insert. In some instances the clamping member includes first and second tabs movable in channels in first and second flanges of the insert.

RELATED APPLICATIONS

This application claims the benefit of priority to European PatentApplication Serial No. 15290148.4, filed Jun. 4, 2015, the content ofwhich is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The disclosure is directed to a vertebral stabilization system. Moreparticularly, the disclosure is directed to a dynamic stabilizationsystem and components thereof.

BACKGROUND

The spinal column of a patient includes a plurality of vertebrae linkedto one another by facet joints and an intervertebral disc locatedbetween adjacent vertebrae. The facet joints and intervertebral discallow one vertebra to move relative to an adjacent vertebra, providingthe spinal column a range of motion. Diseased, degenerated, damaged, orotherwise impaired facet joints and/or intervertebral discs can causethe patient to experience pain or discomfort and/or loss of motion, thusprompting surgery to alleviate the pain and/or restore motion of thespinal column.

One possible method of treating these conditions is to immobilize aportion of the spine to allow treatment. Traditionally, immobilizationhas been accomplished by rigid stabilization. For example, in aconventional spinal fusion procedure, a surgeon restores the alignmentof the spine or the disc space between vertebrae by installing a rigidfixation rod between pedicle screws secured to adjacent vertebrae. Bonegraft is placed between the vertebrae, and the fixation rod cooperateswith the screws to immobilize the two vertebrae relative to each otherso that the bone graft can fuse with the vertebrae.

Dynamic stabilization has also been used in spinal treatment procedures.Dynamic stabilization does not result in complete immobilization, butinstead permits a degree of mobility of the spine while also providingsufficient support and stabilization to effect treatment. One example ofa dynamic stabilization system is the Dynesys® system available fromZimmer Spine, Inc. of Minneapolis, Minn. Such dynamic stabilizationsystems typically include a flexible member positioned between pediclescrews installed in adjacent vertebrae of the spine. A flexible cord canbe threaded through the bore in the flexible member and secured to thepedicle screws while cooperating with the flexible member to permitmobility of the spine.

There is an ongoing need to provide alternative devices, assemblies,systems and/or methods that can function to alleviate pain ordiscomfort, provide stability, such as dynamic stability, and/or restorea range of motion to a spinal segment of a spinal column.

SUMMARY

The disclosure is directed to several alternative designs, materials andmethods of manufacturing medical device structures and assemblies anduses thereof.

Accordingly, one illustrative example is a spinal stabilization systemcomprising an insert positionable in a channel of a housing of avertebral anchor and a support construct including a spacer and firstand second cords extendable through the spacer. The insert has a firstend positionable on a first side of the housing of the vertebral anchorand a second end positionable on a second side of the housing of thevertebral anchor. The first and second cords are positionable throughthe insert.

Additionally or alternatively, in another example, the insert includes afirst bore for receiving the first cord therethrough and a second borefor receiving the second cord therethrough.

Additionally or alternatively, in another example the system includes avertebral anchor including a housing defining a channel and a fastenerconfigured to rotatably engage the housing of the vertebral anchor.Rotational engagement of the fastener with the housing causes thefastener clamp both the first and second cords in the insert.

Additionally or alternatively, in another example the fastener directlycontacts each of the first and second cords to exert a clamping forcedirectly on the first and second cords.

Additionally or alternatively, in another example the fastener includesa threaded portion and a protuberance extending from the threadedportion, wherein the protuberance is extendable into an opening of theinsert to contact each of the first and second cords.

Additionally or alternatively, in another example the opening intersectswith each of the first and second bores.

Additionally or alternatively, in another example rotational engagementof the fastener with the housing causes the fastener clamp both thefirst and second cords in the insert and secure the insert in thehousing of the vertebral anchor.

Additionally or alternatively, in another example the first bore extendsparallel to and offset from the second bore, and the opening extendsperpendicular to and between the first and second bores.

Additionally or alternatively, in another example the vertebral anchorincludes a threaded shaft extending from the housing, wherein thethreaded shaft has a lumen extending therethrough for advancement over aK-wire.

Additionally or alternatively, in another example the opening extendsentirely through the insert such that the insert is advanceable over theK-wire into the housing of the vertebral anchor with the K-wirepositionable between the first and second cords.

Another illustrative example is a spinal stabilization system includingan insert securable to a housing of a vertebral anchor, a supportconstruct including a spacer and a cord extendable through the spacer,and a clamping member. The insert has a first flange positionable on afirst side of the housing of the vertebral anchor, a second flangepositionable on a second side of the housing of the vertebral anchor,and a medial portion between the first and second flanges positionablein a channel of the housing of the vertebral anchor. The cord ispositionable through a bore of the insert. The clamping member ismovable relative to the medial portion to clamp the cord in the bore ofthe insert.

Additionally or alternatively, in another example the clamping memberincludes a concave engagement surface configured to press against aportion of the periphery of the cord, preferably 30 degrees or more ofthe periphery of the cord.

Additionally or alternatively, in another example the clamping memberincludes a first tab movable in a channel in the first flange and asecond tab movable in a channel in the second flange.

Additionally or alternatively, in another example the clamping member isconfigured to be held in a loading position prior to clamping onto thecord.

Additionally or alternatively, in another example each of the channelshas an upper portion having a first width and a lower portion having asecond width, the first width being less than the width of the first andsecond tabs to form an interference fit with the first and second tabs,and the second width being greater than the width of the first andsecond tabs.

The above summary of some example embodiments is not intended todescribe each disclosed embodiment or every implementation of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be more completely understood in consideration of thefollowing detailed description of various embodiments in connection withthe accompanying drawings, in which:

FIG. 1 is a perspective view of an exemplary spinal stabilizationsystem;

FIG. 2 is an exploded perspective view of components of the spinalstabilization system of FIG. 1, including an insert positionable in athe channel of the housing of the pedicle screw;

FIG. 3 is a perspective view of the insert of spinal stabilizationsystem of FIG. 1;

FIG. 4 is an exploded perspective view of the insert of FIG. 3;

FIG. 5A is a cross-sectional view of the insert positioned in thehousing of the pedicle screw of the spinal stabilization system prior tosecurement of the insert in the housing;

FIG. 5B is a cross-sectional view of the insert secured in the housingof the pedicle screw of the spinal stabilization system;

FIGS. 6A through 6C illustrate exemplary configurations of an insert ofa spinal stabilization system;

FIG. 7 is a perspective view of another exemplary insert of a spinalstabilization system;

FIG. 8 is a top view of the insert of FIG. 7;

FIG. 9 is a cross-sectional view of the insert taken along line 9-9 ofFIG. 8;

FIGS. 10A and 10B are longitudinal cross-sectional views of the insertof FIG. 7 while securing a flexible cord within the insert;

FIG. 10C is a longitudinal cross-sectional view of the insert of FIG. 7in an alternate orientation within a vertebral anchor;

FIG. 11A is a perspective view of another exemplary insert of a spinalstabilization system;

FIG. 11B is a longitudinal cross-sectional view of the insert of FIG.11A;

FIG. 12A is a perspective view of another exemplary insert of a spinalstabilization system;

FIG. 12B is a perspective view of another exemplary insert of a spinalstabilization system;

FIG. 13A is a perspective view of another exemplary insert of a spinalstabilization system;

FIG. 13B is a perspective view of another exemplary insert of a spinalstabilization system;

FIG. 14 is a perspective view of another exemplary insert and associatedlocking member of a spinal stabilization system;

FIG. 15 is a longitudinal cross-sectional view of a spinal stabilizationsystem utilizing inserts as shown in FIG. 14;

FIG. 16 is a top view of a portion of the spinal stabilization system ofFIG. 15;

FIG. 17 is an exploded view of components of another spinalstabilization system;

FIG. 18A is a longitudinal cross-sectional view of a spinalstabilization system utilizing the components of FIG. 16;

FIG. 18B is an enlarged view of a portion of FIG. 17A;

FIG. 19 is a top view of a portion of the spinal stabilization system ofFIG. 17A;

FIG. 20 is an exploded view of components of another spinalstabilization system;

FIG. 21 is a longitudinal cross-sectional view of the spinalstabilization system of FIG. 19;

FIG. 22 is a perspective view of another spinal stabilization system;

FIG. 23A is a longitudinal cross-sectional view of the spinalstabilization system of FIG. 22;

FIG. 23B is an enlarged view of a portion of FIG. 23A;

FIG. 24 is a perspective view of an insert and associated locking memberof the spinal stabilization system of FIG. 22;

FIG. 25 is a cross-sectional view of the insert of FIG. 24;

FIG. 26 is a cross-sectional view of the insert of FIG. 25; and

FIG. 27 is a cross-sectional view of the insert of FIG. 24 secured inthe housing of a pedicle screw of the spinal stabilization system ofFIG. 23A.

While the invention is amenable to various modifications and alternativeforms, specifics thereof have been shown by way of example in thedrawings and will be described in detail. It should be understood,however, that the intention is not to limit aspects of the invention tothe particular embodiments described. On the contrary, the intention isto cover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention.

DETAILED DESCRIPTION

For the following defined terms, these definitions shall be applied,unless a different definition is given in the claims or elsewhere inthis specification.

All numeric values are herein assumed to be modified by the term“about”, whether or not explicitly indicated. The term “about” generallyrefers to a range of numbers that one of skill in the art would considerequivalent to the recited value (i.e., having the same function orresult). In many instances, the term “about” may be indicative asincluding numbers that are rounded to the nearest significant figure.

The recitation of numerical ranges by endpoints includes all numberswithin that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4,and 5).

Although some suitable dimensions ranges and/or values pertaining tovarious components, features and/or specifications are disclosed, one ofskill in the art, incited by the present disclosure, would understanddesired dimensions, ranges and/or values may deviate from thoseexpressly disclosed.

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” include plural referents unless the contentclearly dictates otherwise. As used in this specification and theappended claims, the term “or” is generally employed in its senseincluding “and/or” unless the content clearly dictates otherwise.

The following detailed description should be read with reference to thedrawings in which similar elements in different drawings are numberedthe same. The detailed description and the drawings, which are notnecessarily to scale, depict illustrative embodiments and are notintended to limit the scope of the invention. The illustrativeembodiments depicted are intended only as exemplary. Selected featuresof any illustrative embodiment may be incorporated into an additionalembodiment unless clearly stated to the contrary.

Referring now to FIG. 1, there is shown a spinal fixation system 10 forstabilizing a portion of a spinal column, such as one or more spinalsegments of a spinal column. As used herein, a spinal segment isintended to refer to two or more vertebrae, the intervertebral disc(s)between the vertebrae and other anatomical elements between thevertebrae. For example, a spinal segment can include first and secondadjacent vertebrae and the intervertebral disc located between the firstand second vertebrae. The spinal stabilization system 10 can providedynamic stabilization to a spinal segment, preserving and/or allowingfor a range of motion of the spinal segment.

In some embodiments, the spinal stabilization system 10 can be used totreat discogenic low back pain, degenerative spinal stenosis, discherniations, facet syndrome, posterior element instability, adjacentlevel syndrome associated with spinal fusion, and/or other maladiesassociated with the spinal column.

The spinal stabilization system 10 can include one or more or aplurality of vertebral anchors, depicted as pedicle screws 12. However,in some embodiments the vertebral anchors can be vertebral hooks (e.g.,laminar hooks) or other types of fastening members for attachment to abony structure such as a vertebra of the spinal column. Each of thepedicle screws 12 can be configured to be secured to a vertebra of aspinal column. For instance, the first pedicle screw 12 a can be securedto a first vertebra and the second pedicle screw 12 b can be secured toa second vertebra. Additional pedicle screws 12 can be present ininstances in which the spinal stabilization system 10 spans three ormore vertebra of the spinal column.

The pedicle screw 12 can include a housing 14 and a shaft 16, which caninclude threads 18, extending from the housing 14. The housing 14 caninclude a channel, such as a U-shaped channel extending from one side ofthe housing 14 to an opposite second side of the housing 14. The channel15 (see FIG. 2) can be defined between opposing legs of the housing 14.The shaft 16 can be configured to be installed into a bony region of avertebra of the spinal column. For example, the shaft 16 can beinstalled into a pedicle of a vertebra, or other region of a vertebra.The shaft 16 can extend along a longitudinal axis. The pedicle screw 12depicted in the Figures is a poly-axial pedicle screw which allows thehousing 14 to be pivotable relative to the shaft 16 to a plurality ofangular positions relative to the longitudinal axis. The pedicle screw12, as shown in FIG. 2, can include a head portion 17 at the end of theshaft 16 which is received in the housing 14. The housing 14 can bepivotable relative to the head portion 17 of the shaft 16. In otherinstances, the pedicle screw 12 can be mono-axial or mono-planar, ifdesired.

The pedicle screw 12 can include a securing element, such as a threadedfastener 20 (e.g., a set screw, cap) configured to rotatably engage thehousing 14 to secure a portion of a support construct 22 to the pediclescrew 12. For example, the threaded fastener 20 can include threadswhich mate with threads formed in the housing 14. In other embodiments,the fastener 20 can include one or more flanges, cam surfaces, or otherengagement features that engage with one or more channels, grooves,surfaces, or other engagement features of the housing 14 throughrotation of the fastener 20. The fastener 20 can be rotatably engagedbetween spaced apart legs of the housing 14 which define the channel 15of the housing 14 therebetween.

The spinal stabilization system 10 can also include one or more, or aplurality of support constructs 22 extending between pedicle screws 12of the spinal stabilization system 10. As an illustrative example, thespinal stabilization system 10 shown in FIG. 1 includes a supportconstruct 22 extending between the first pedicle screw 12 a and thesecond pedicle screw 12 b.

The support construct 22 can be constructed of a plurality of componentsin some instances. For instance, the support construct 22 can include aspacer 24, and a flexible member such as a flexible cord 30 extendingthrough the spacer 24, as well as other components if desired.

In some embodiments, the spacer 24 can be an annular spacer having alumen (not shown) extending from a first end 26 to a second end 28 ofthe spacer 24. For example, in some embodiments the spacer 24 can be acylindrical member having a lumen extending therethrough. In otherembodiments, the spacer 24 can be molded, extruded, or otherwise formedover and/or around the cord 30. The spacer 24 can be positioned betweenthe housing 14 of the first pedicle screw 12 a and the housing 14 of thesecond pedicle screw 12 b. In some embodiments, the spacer 24 can beformed from polycarbonate urethane (PCU), although it will be recognizedthat various other materials suitable for implantation within the humanbody and for providing stabilization of the spine while maintainingflexibility can be used. In other embodiments, the spacer 24 can beconstructed of other materials such as metal, polymeric materials, orcombinations of materials.

The cord 30 can extend from the housing 14 of the first pedicle screw 12a to the housing 14 of the second pedicle screw 12 b. In one embodiment,the cord 30 can be formed from polyethylene-terephthalate (PET),although it will be recognized that various other materials suitable forimplantation within the human body and for providing stabilization ofthe spine while maintaining flexibility can be used. In otherembodiments, the cord 30 can be constructed of other flexible materialssuch as metal, polymeric materials, or combinations of flexiblematerials. It is noted that during a medical procedure the portions ofthe cord 30 which are shown extending from the channels of the pediclescrews 12 a, 12 b can be trimmed as desired to reduce and/or eliminatethe portion of the cord 30 extending from the pedicle screws 12 a, 12 b.

When implanted in a patient, the cord 30 of the spinal stabilizationsystem 10 can limit the range of flexion of the spinal segment, whereasthe spacer 24 can limit the range of extension of the spinal segment.For instance, the cord 30 can be placed in tension and the spacer 24 canbe placed in compression between the pedicle screws 12 a, 12 b.

The spinal stabilization system 10 can also include inserts 32configured to be inserted into the channels 15 of the housings 14 of thepedicle screws 12. One possible embodiment of the insert 32 is furtherillustrated in FIGS. 3 and 4. The inserts 32, which can be consideredspools in some instances, can include a first flange 34 proximate afirst end of the insert 32, a second flange 36 proximate the second endof the insert 32, and a medial portion 38 intermediate the first flange34 and the second flange 36 and extending therebetween. The insert 32can have end surfaces 48 configured to abut an end surface of the spacer24. For instance, when assembled an end surface 48 of an insert 32coupled with the first pedicle screw 12 a can abut an end surface of thespacer 24 proximate the first end 26 of the spacer 24 and an end surface48 of an insert 32 coupled with the second pedicle screw 12 b can abutan end surface of the spacer 24 proximate the second end 28 of thespacer 24.

The insert 32 can be configured such that the medial portion 38 ispositionable in the channel 15 (shown in FIG. 2) of the housing 14 ofthe pedicle screw 12 with the first flange 34 positioned exterior of thehousing 14 and facing the first side of the housing 14 and the secondflange 36 positioned exterior of the housing 14 and facing the secondside of the housing 14. The insert 32 can be positioned in the channel15 in a top-loaded fashion in which the insert 32 is moved into thechannel 15 of the housing 14 in a direction generally perpendicular tothe longitudinal axis of the channel 15 of the housing 14.

The insert 32 can include bore 40 extending from a first end surface 48at the first end of the insert 32 to a second end surface 48 at thesecond end of the insert 32 along a longitudinal axis through the insert32. The bore 40 can be configured to receive the cord 30 therein. Forinstance, the cord 30 can be inserted into and/or through the bore 40 ofthe insert 32. Thus, the cord 30 can extend out of the bore 40 from thefirst end surface 48 at the first end of the insert 32 in a firstdirection and/or the cord 30 can extend out of the bore 40 from thesecond end surface 48 at the second end of the insert 32 in a seconddirection opposite the first direction.

The insert 32 can include a clamping member 50 configured to clamp orsecure the cord 30 within the bore 40 of the insert 32. For example, theclamping member 50 can be inserted into an opening 42 in the medialportion 38 of the insert 32 to bear against the cord 30. The opening 42can intersect with the bore 40 to provide direct engagement of theclamping member 50 with a portion of the cord 30 positioned in the bore40. In some instances, the insert 32 can be press fit in the opening 42.As shown in FIG. 3, in some instances, the clamping member 50 can beinserted into the opening 42 until the exterior surface of the clampingmember 50 is flush with an exterior surface of the medial portion 38 ofthe insert 32.

The clamping member 50 can include any mechanical gripping means suchas, but not limited to, one or more ribs, projecting grooves, teeth,posts, spikes, and/or serrations or combination thereof for engagingand/or penetrating into the cord 30. In the illustrated embodiment, theclamping member 50 can include a generally concave engagement surface 44having a plurality of ribs, teeth, serrations, grooves, or othergripping features formed along the concave surface 44, configured toengage and/or penetrate into the cord 30. As shown in FIG. 5A, theconcave engagement surface 44 can be configured to engage the peripheryof the cord 30, such as 30 degrees or more, 45 degrees or more, 60degrees or more, 75 degrees or more, or 90 degrees or more around theperiphery (e.g., circumference) of the cord 30 when engaging the cord 30in the bore 40.

In some instances, the cord 30 can be pre-assembled with the insert 32and secured in the bore 40 with the clamping member 50 by pressing theclamping member 50 against the cord 30 prior to inserting the insert 32into the channel 15 of the housing 14 of the pedicle screw 12.Additionally or alternatively, the cord 30 can be intra-operativelysecured in the bore 40 with the clamping member 50 while securing theinsert 32 in the channel 15 of the housing 14 of the pedicle screw 12with the fastener 20.

One exemplary configuration for securing the cord 30 in the bore 40while simultaneously locking the housing 14 of the poly-axial pediclescrew 12 from pivotal movement is shown in FIGS. 5A and 5B.

As shown in FIG. 5A, the insert 32 can be inserted into the channel 15of the housing 14 in a direction generally perpendicular to thelongitudinal axis of the bore 40. The cord 30, extending into or throughthe bore 40 of the insert 32, can also be inserted into the channel 15of the housing 14 with the cord 30 extending from the first side of thehousing 14 and/or extending from the second side of the housing 14.Thus, the medial portion 38 of the insert 32 can be positioned withinthe U-shaped channel 15.

The fastener 20 can then be engaged with the housing 14, such as throughrotational movement of the fastener 20 relative to the housing 14. Insome instances, the fastener 20 can include a threaded portion whichthreadably engages a threaded portion of the housing 14, such asinternally threaded portions of opposing legs of the housing 14 definingthe channel 15. Rotational movement of the fastener 20 moves thefastener 20 into engagement with the insert 32.

As shown in FIG. 5B, rotational engagement of the fastener 20 with thehousing 14 causes the fastener 20 to directly contact the clampingmember 50 to exert a force on the clamping member 50 to push theclamping member 50 toward the cord 30. The amount of rotation of thefastener 20, and thus axial movement of the fastener 20 along its axisof rotation, controls the displacement of the clamping member 50 in theopening 42 toward the cord 30. The concave surface 44 of the clampingmember 50 can contact a portion of the periphery (e.g., circumference)of the cord 30, such as 5% or more, 10% or more, 15% or more, 20% ormore, or 25% or more of the periphery of the cord 30. Deformation of thecord 30 and/or penetration into the cord 30 by the clamping member 50can prevent the cord 30 from moving axially through the bore 40 of theinsert 32.

In some instances, the clamping force generated through rotationalengagement of the fastener 20 with the housing 14 both clamps the cord30 to the insert 32 (and thus secures the cord 30 to the pedicle screw12) and locks the housing 14 from pivotal movement relative to the shaft16 of the pedicle screw 12. For instance a locking force exerted by thefastener 20 can be transmitted through the insert 32 to the head portion17 of the shaft 16 to lock the housing 14 from pivotable movementrelative to the head portion 17 of the shaft 16. When the clamping forceis sufficiently large, the clamping force exerted onto the head portion17 by the insert 32 locks the housing 14 from pivotal movement relativeto the head portion 17.

As shown in FIGS. 6A-6C, the end surfaces 48 of the insert 32 can beoriented at any desired angle relative to the longitudinal axis of thebore 40 extending through the insert 32. For example, in FIG. 6A, theboth the first and second end surfaces 48 of the insert 32 can begenerally perpendicular to the longitudinal axis of the bore 40. Inother instances, one or more of the end surfaces 48 can be oriented atan oblique angle to the longitudinal axis of the bore 40, such as foruse in lordotic applications. For example, in FIG. 6B, the first endsurface 48 of the insert 32 can be at an oblique angle θ to thelongitudinal axis of the bore 40, while the second end surface 48 of theinsert can be generally perpendicular to the longitudinal axis of thebore 40. Alternatively, in FIG. 6C, the first end surface 48 of theinsert 32 can be at an oblique angle θ₁ to the longitudinal axis of thebore 40 and the second end surface 48 of the insert 32 can be at anoblique angle θ₂ to the longitudinal axis of the bore 40. The angles θ₁and θ₂ can be the same or different. The angles θ₁, θ₂ and/or θ can beany desired angle, such as 2°, 3°, 4°, 5°, 6°, 7°, 8°, 9° or 10°, forexample. It is note that any of the embodiments of an insert describedherein can include end surfaces which are perpendicular and/or obliqueto the longitudinal axis of the bore extending through the insert.

Another embodiment of an insert 132 configured for securement of thecord 30 within the housing 14 of a pedicle screw 12 or other vertebralanchor is illustrated in FIGS. 7-9. The insert 132 can be similar to theinsert 32 in many respects. For example, the insert 132 can include afirst flange 134 proximate a first end of the insert 132, a secondflange 136 proximate the second end of the insert 132, and a medialportion 138 intermediate the first flange 134 and the second flange 136and extending therebetween. The insert 132 can have end surfaces 148configured to abut an end surface of the spacer 24. The insert 132 canbe configured such that the medial portion 138 is positionable in thechannel 15 of the housing 14 of the pedicle screw 12 with the firstflange 134 positioned exterior of the housing 14 and facing the firstside of the housing 14 and the second flange 136 positioned exterior ofthe housing 14 and facing the second side of the housing 14.

The insert 132 can include bore 140 extending from a first end surface148 at the first end of the insert 132 to a second end surface 148 atthe second end of the insert 132 along a longitudinal axis through theinsert 132. The bore 140 can be configured to receive the cord 30therein.

The insert 132 can include a clamping member 150 configured to clamp orsecure the cord 30 within the bore 140 of the insert 132. For example,the clamping member 150 can be movable relative to the medial portion138 of the insert 132 to bear against the cord 30 and clamp the cord 30therebetween. The clamping member 150 can include a first tab 152extending into a channel 146 in the first flange 134 and a second tab152 extending into a channel 146 in the second flange 136. The tabs 152can move along the channels 146 as the clamping member 150 is movedtoward the cord 30 to clamp the cord 30 in the bore 140. In someinstances, such as shown in FIG. 8, the tabs 152 can form aninterference fit with the channels 146 such that walls of the tabs 152frictionally engage walls of the channels 146 to resist movement of theclamping member 150 relative to the medial portion 138 of the insert 132unless and until the force sufficient to overcome thefrictional/interference force is overcome. As shown in FIG. 9, in someinstances the upper portion of the channels 146 can have a width W₁ anda lower portion of the channels 146 can have a width W₂ greater than thewidth W₁. The tabs 152 can have a width greater than the width W₁ toprovide an interference fit in the upper portion of the channel 146.However, the width of the tabs 152 can be less than the width W₂ of thelower portion of the channel 146. Thus, as shown in FIG. 10A, theclamping member 150 can be initially positioned in a first, loadingposition with the tabs 152 forming an interference fit in the upperportion of the channel 146, retaining the clamping member 150 in theloading position such that the clamping member 150 does not interferewith positioning the cord 30 into and/or through the bore 140 of theinsert 132. Upon applying sufficient force to the clamping member 150 toovercome the frictional force (e.g., tightening the fastener 20 in thehousing 14 of the pedicle screw 12 to apply a force against the clampingmember 150), the tabs 152 move into the wider lower portion of thechannel 146 to the clamped position, shown in FIG. 10B, with theclamping member 150 engaging and/or penetrating into the cord 30 tosecure the cord 30 in the bore 140 of the insert 132.

It is noted that other configurations are contemplated for initiallyholding the clamping member 150 in a loading position to facilitatepositioning the cord 30 in the bore 140. For example, detents can beincorporated with the tabs 152/channels 146 to form an interferencebetween the components.

The clamping member 150 can include any mechanical gripping means suchas, but not limited to, one or more ribs, projecting grooves, teeth,posts, spikes, and/or serrations or combination thereof for engagingand/or penetrating into the cord 30. In the illustrated embodiment ofFIGS. 10A-10C, the clamping member 150 can include a generally concaveengagement surface having a plurality of ribs, teeth, serrations,grooves, or other gripping features formed along the concave surface,configured to engage and/or penetrate into the cord 30. The concaveengagement surface can be configured to engage the periphery of the cord30, such as 30 degrees or more, 45 degrees or more, 60 degrees or more,75 degrees or more, or 90 degrees or more around the periphery (e.g.,circumference) of the cord 30 when engaging the cord 30 in the bore 140.

Additionally or alternatively to the embodiment of FIGS. 10A-10C, themedial portion 138 of the insert 132 can include any mechanical grippingmeans such as, but not limited to, one or more ribs, projecting grooves,teeth, posts, spikes, and/or serrations or combination thereof forengaging and/or penetrating into the cord 30. In the illustratedembodiment of FIG. 12B, the medial portion 138 can include a generallyconcave engagement surface having a plurality of ribs, teeth,serrations, grooves, or other gripping features formed along the concavesurface, configured to engage and/or penetrate into the cord 30. Theconcave engagement surface can be configured to engage the periphery ofthe cord 30, such as 30 degrees or more, 45 degrees or more, 60 degreesor more, 75 degrees or more, or 90 degrees or more around the periphery(e.g., circumference) of the cord 30 when engaging the cord 30 in thebore 140.

In some instances, the cord 30 can be pre-assembled with the insert 132and secured in the bore 140 with the clamping member 150 by pressing theclamping member 150 against the cord 30 prior to inserting the insert132 into the channel 15 of the housing 14 of the pedicle screw 12.Additionally or alternatively, the cord 30 can be intra-operativelysecured in the bore 140 with the clamping member 150 while securing theinsert 132 in the channel 15 of the housing 14 of the pedicle screw 12with the fastener 20.

FIG. 10C illustrates another possible orientation of the insert 132positioned in the channel of the housing 14 of a pedicle screw (shown inphantom). As shown in FIG. 10C, in some instances the insert 132 can bepositioned in the channel of the housing 14 of the pedicle screw 12 withthe clamping member 150 below or distal the medial region 138 of theinsert 132, with the flanges 134, 136 positioned on opposite sides ofthe housing 14, if desired. Upon applying sufficient force to theclamping member 150 to overcome the frictional force between the tabs152 and channels 146 (e.g., tightening the fastener 20 in the housing 14of the pedicle screw 12 to apply a force against the medial region 138),the medial region 138 and first and second flanges 134, 136 movedownward relative to the housing 14 to clamp the cord 30 between themedial region 138 and clamping member 150. As the medial region 138 andflanges 134, 136 move relative to the housing 14 and clamping member150, the tabs 152 move into the wider lower portion of the channel 146to the clamped position, with the clamping member 150 engaging and/orpenetrating into the cord 30 to secure the cord 30 in the bore 140 ofthe insert 132. Accordingly, in some instances the fastener 20 can bearagainst the medial region 138 of the insert 132 while the clampingmember 150 can bear against a component of the housing 14, for example.

FIGS. 11A and 11B illustrate insert 132′, which is a variation of theinsert 132. Unlike the embodiment of FIGS. 7-8, in which the channels146 extend to the outer peripheral edge of the flanges 134, 136, in thevariation of FIGS. 11A and 11B, the channels 146 may not extend to theouter peripheral edge of the flanges 134, 136. Such an embodiment canhelp retain the clamping member 150 assembled with the main body of theclamping member 150 during assembly of the construct. FIGS. 12A and 12Billustrate insert 132″, which is a variation of the insert 132′illustrating that the width of the channels 146 and tabs 152 can be upto about the diameter of the bore 140.

FIGS. 13A and 13B illustrate insert 132′″, which is a variation of theinsert 132″. Unlike the embodiment of FIGS. 12A-12B, in which thechannels 146 and tabs 152 each have a uniform width, in the variation ofFIGS. 13A and 13B, the upper portion of the channels 146 can have aprotuberance extending radially towards the bore 140 and the tabs 152can have a void disposed therein that receives the protuberance inmating engagement.

It is noted that in other instances, the insert 132, 132′ can includechannels at opposing ends of the clamping member 150 configured to matewith and receive projections extending into the channels from theflanges 134, 136. In other instances, the insert 132, 132′ can include achannel at a first end of the clamping member 150 configured to matewith and receive a projection extending into the channels from one ofthe flanges 134, 136 and a tab extending from the opposite, second endof the clamping member 150 configured to mate with and extend into achannel in the other of the flanges 134, 136.

Another embodiment of an insert 232 configured for securement of thecord 30 within the housing 14 of a pedicle screw 12 or other vertebralanchor is illustrated in FIG. 13. The insert 232 can be similar to theinsert 32 in many respects. For example, the insert 232 can include afirst flange 234 proximate a first end of the insert 232, a secondflange 236 proximate the second end of the insert 232, and a medialportion 238 intermediate the first flange 234 and the second flange 236and extending therebetween. The insert 232 can have end surfaces 248configured to abut an end surface of the spacer 24. The insert 232 canbe configured such that the medial portion 238 is positionable in thechannel 15 of the housing 14 of the pedicle screw 12 with the firstflange 234 positioned exterior of the housing 14 and facing the firstside of the housing 14 and the second flange 236 positioned exterior ofthe housing 14 and facing the second side of the housing 14.

The insert 232 can include bore 240 extending from a first end surface248 at the first end of the insert 232 to a second end surface 248 atthe second end of the insert 232 along a longitudinal axis through theinsert 232. The bore 240 can be configured to receive the cord 30therein.

The insert 232 can include an opening 242 in the medial portion 238 ofthe insert 232 for receiving a clamping member to bear against the cord30. The opening 242 can intersect with the bore 240 to provide directengagement of the clamping member with a portion of the cord 30positioned in the bore 240. The clamping member can be a fastener 220,such as a threaded set screw including threads which mate with threadsformed in the housing 14. The fastener 220 can be rotatably engagedbetween spaced apart legs of the housing 14 to apply a clamping force tothe cord 30 to clamp or secure the cord 30 within the bore 240 of theinsert 232 while simultaneously clamping the insert 232 in the housing14 of a pedicle screw 12. For example, the fastener 220 can include athreaded portion 226 and a protuberance 224 extending from the threadedportion 226. The protuberance 224 can extend into the opening 242 tobear against the cord 30 and clamp the cord 30 in the bore 240.

The insert 232 can also include recesses 260 formed in the flanges 234,236 of the insert 232 to accommodate the fastener 220 therebetween. Forinstance, as shown in FIG. 16, the fastener 220 can have an outerdiameter greater than the distance between the first flange 234 and thesecond flange 236 (i.e., the distance between the inner surfaces of theflanges 234, 236 facing the medial portion 238. Thus, the recesses 260can provide clearance for the fastener 220 to be rotatably engaged withthe housing 14 of the pedicle screw 12 between the first and secondflanges 234, 236. Furthermore, the recesses 260 can allow for a degreeof rotational variability of the insert 232 (about the longitudinal axisof the bore 240) relative to the housing 14 when positioning andsecuring the insert 232 in the housing 14.

FIG. 15 illustrates a support construct 222 utilizing inserts 232. Thesupport construct 222 can also include spacers 24 and a flexible membersuch as a flexible cord 30 extending through the spacers 24, as well asother components if desired. The inserts 232 are shown positioned in thehousing 14 of the pedicle screws 12, with spacers 24 positioned betweenfacing surfaces of the inserts 232. The flexible cord 30 can extendthrough the bores 240 of the inserts 232 and the lumen of the spacers24. The fasteners 220 can be threadably engaged with the housing 14 ofthe pedicle screws 12 to secure the inserts 232 to the housing 14 whilethe protuberance 224 of the inserts 232 can simultaneously engage thecord 30 to secure the cord 30 relative to the insert 232 and housing 14.

Furthermore, the end of the cord 30 can be secured to a rigid rod member270, providing a transition between the dynamic or flexible portion ofthe construct 222 and a rigid portion of the construct 222. The rigidrod 270 can extend to one or more additional pedicle screws (not shown),for example.

The rigid rod member 270 can include an end region configured to besecured to an end region of the cord 30. For example, end region of therigid rod member 270 can be configured as a clam shell connector havinga plurality of segments 272 collectively defining a bore for receivingthe end region of the cord 30. The segments 272 can extend from a flange274 of the rigid rod member 270 positionable on a first side of thehousing 14 of the pedicle screw 12. The free ends of the segments 272can move toward one another (e.g., radially inward toward the centrallongitudinal axis of the cord 30 to clamp around the cord 30. Forexample, a clamping force can be exerted on the segments 272 to move thefree ends toward one another. A retaining ring 276 can be slid over thecord 30 and placed around the free ends of the segments 272 to securethe cord 30 and prevent the free ends of the segments 272 fromseparating. The segments 272 of the clam shell connector can bepositioned in the channel of the housing 14 of the pedicle screw 12 withthe flange 274 on a first side of the housing 14 and the retaining ring276 on a second, opposite side of the housing 14. The retaining ring 276can act as a flange for engagement with a spacer 24 of the supportconstruct 222.

Components of another exemplary support construct 322 utilizing inserts332 are shown in FIG. 17. It is noted that the inserts 332 can besubstituted with any other configuration of insert described herein, ifdesired. The support construct 322 includes inserts 332 for securementin the housings 14 of pedicle screws 12 or other vertebral anchors, aswell as spacers 24 and a flexible member such as a flexible cord 30extending through the spacers 24 and secured in the inserts 332.

The inserts 332 can be similar to the other inserts 332 described hereinin many respects. For example, the inserts 332 can include a firstflange 334 proximate a first end of the insert 332, a second flange 336proximate the second end of the insert 332, and a medial portion 338intermediate the first flange 334 and the second flange 336 andextending therebetween. The insert 332 can be configured such that themedial portion 338 is positionable in the channel 15 of the housing 14of the pedicle screw 12 with the first flange 334 positioned exterior ofthe housing 14 and facing the first side of the housing 14 and thesecond flange 336 positioned exterior of the housing 14 and facing thesecond side of the housing 14.

The insert 332 can include bore 340 extending from a first end surfaceat the first end of the insert 332 to a second end surface at the secondend of the insert 332 along a longitudinal axis through the insert 332.The bore 340 can be configured to receive the cord 30 therein.

The insert 332 can include one or more, or a plurality of openings 342in the medial portion 338 of the insert 332 for receiving a clampingmember to bear against the cord 30. The openings 342 can intersect withthe bore 340 to provide direct engagement of the clamping member with aportion of the cord 30 positioned in the bore 340. The clamping memberscan be pins 350 press fit, or otherwise positioned in the openings 342.

The insert 332 can also include recesses 360 formed in the flanges 334,336 of the insert 332 to accommodate the fastener 20 therebetween. Forinstance, as shown in FIG. 19, the fastener 20 can have an outerdiameter greater than the distance between the first flange 334 and thesecond flange 336 (i.e., the distance between the inner surfaces of theflanges 334, 336 facing the medial portion 338. Thus, the recesses 360can provide clearance for the fastener 20 to be rotatably engaged withthe housing 14 of the pedicle screw 12 between the first and secondflanges 334, 336.

FIG. 18A illustrates a support construct 322 utilizing inserts 332. Thesupport construct 322 can also include spacers 24 and a flexible membersuch as a flexible cord 30 extending through the spacers 24, as well asother components if desired. The inserts 332 are shown positioned in thehousing 14 of the pedicle screws 12, with spacers 24 positioned betweenadjacent inserts 332. The flexible cord 30 can extend through the bores340 of the inserts 332 and the lumen of the spacers 24. The fasteners 20can be threadably engaged with the housing 14 of the pedicle screws 12to secure the inserts 332 to the housing 14. In some instances, thefasteners 20 can drive the pins 350 into clamping engagement with thecord 30 as the fasteners 20 are threadably engaged with the housing 14of the pedicle screw 12. In other instances, the drive pins 350 can bepressed against the cord 30 prior to inserting the inserts 332 into thehousing 14 of the pedicle screw 12.

The support construct 322 can also include one or more rings 380positionable between an end surface of an insert 332 and an end surfaceof a spacer 24. In some instances, the use of the ring 380 can betweenthe insert 332 and the spacer 24 can provide a desired amount ofangulation between the longitudinal axis of the bore 340 of the insert332 relative to the lumen of the spacer 24 such that the central axis ofthe lumen of the spacer 24 extends non-parallel (e.g., oblique) to thecentral axis of the bore 340 of the insert 332.

As shown in in the enlarged view of FIG. 18B, the ring 380 can includean annular portion 382 with an opening 388 extending axially through theannular portion 382 for receiving the cord 30 therethrough. The annularportion 382 can have a first face 392 configured to face and abut an endsurface of a flange of the insert 332 and an opposite, second face 394configured to face and abut an end surface of a spacer 24. The firstface 392 can be non-parallel to the second face 394 providing theannular portion 382 with a wedge-shape. The angle between the first face392 and the second face 394 can be any desired angle, such as 2°, 3°,4°, 5°, 6°, 7°, 8°, 9° or 10°, for example.

In some instances the ring 380 can include an annular projection 384extending from the second face 394 of the annular portion 382. Theopening 388 can extend through the annular projection 384, and thus thecord 30 can extend through the annular projection 384. The annularprojection 384 can be configured to extend into the lumen of the spacer24, such as an enlarged recessed portion at an end region of the spacer24. Additionally or alternatively, the ring 380 can include annularprojection 386 extending from the first face 392 of the annular portion382. The opening 388 can extend through the annular projection 386, andthus the cord 30 can extend through the annular projection 386. Theannular projection 386 can be configured to extend into the bore 340 ofthe insert 332, such as an enlarged recessed portion in a flange of theinsert 332.

In some instances, the ring 380 can include an engagement featureconfigured to mate with an engagement feature of the insert 332 and/orthe spacer 24 to orient the ring 380 at a desired rotational positionrelative to the insert 332 positioned on a first side of the ring 380and/or the spacer 24 positioned on a second side of the ring 380.

FIGS. 20 and 21 illustrate components of another support construct 422including a rigid segment coupled to a flexible segment. The supportconstruct 422 can include an insert 432 positionable in the housing 14of a pedicle screw 12 or other vertebral anchor, forming a transitionbetween a rigid segment and a flexible segment of the support construct422. For example, the rigid segment can include a rigid rod member 470and the flexible segment can include a spacer 24, and a flexible membersuch as a flexible cord 30 extending through the spacer 24, as well asother components if desired. The end of the cord 30 can be secured tothe rigid rod member 470, via the insert 432, providing a transitionbetween the dynamic or flexible portion of the construct 422 and therigid portion of the construct 422.

The insert 432 can include a first flange 434 and a second flange 436spaced from the first flange 434 by a medial region 438. The medialregion 438 can have a cross-sectional dimension less than thecross-sectional dimension of each of the first and second flanges 434,436. For instance, the medial region 438 can be sized for insertion intothe U-shaped channel of the housing 14 of a pedicle screw 12 or othervertebral anchor, with the first flange 434 located exterior of thehousing 14 on a first side of the housing 14 and the second flange 436located exterior of the housing 14 on a second side of the housing 14,similar to other inserts described herein.

The rigid rod member 470 can extend from the second flange 436. In someinstances the rigid rod member 470 can be integrally formed with theinsert 432 as a monolithic construct, however, in other instances therigid rod member 470 can be a separate component attached to the insert432, for example. The rigid rod 470 can be sized to extend to one ormore additional pedicle screws (not shown), for example. The rigid rod470 can be any desired length, such as a length sufficient to extendbetween two, three, four, or more pedicle screws 12 secured tocorresponding vertebrae of the spinal column.

The insert 432 can include a bore 440 extending into the medial region438 from the first flange 434 for receiving a portion of the flexiblecord 30, such as an end portion of the flexible cord 30. The insert 432can also include a clamping member 450 configured to clamp or secure thecord 30 within the bore 440 of the insert 432. For example, the clampingmember 450 can be movable relative to the medial portion 438 of theinsert 432 to clamp the cord 30 between the clamping member 450 and themedial portion 438.

The clamping member 450 can be constructed similar to the clampingmember 150, discussed above. For example, the clamping member 450 caninclude a first tab 452 extending into a channel 446 in the first flange434 and a second tab 452 extending into a channel 446 in the secondflange 436. The tabs 452 can move along the channels 446 as the clampingmember 450 is moved toward the cord 30 to clamp the cord 30 in the bore440. In some instances, the tabs 452 can form an interference fit withthe channels 446 such that walls of the tabs 452 frictionally engagewalls of the channels 446 to resist movement of the clamping member 450relative to the medial portion 438 of the insert 432 unless and untilthe force sufficient to overcome the frictional/interference force isovercome.

The clamping member 450 can include any mechanical gripping means suchas, but not limited to, one or more ribs, projecting grooves, teeth,posts, spikes, and/or serrations or combination thereof for engagingand/or penetrating into the cord 30. In the illustrated embodiment, theclamping member 450 can include one or more, or a plurality ofprotuberances 454 configured to engage and/or penetrate into the cord30.

It is noted that the insert 432 can alternatively be constructed to useany other clamping member to secure the cord 30 in the bore 440, such asany of the other clamping members described herein. Furthermore, it isnoted that any of the other inserts described herein can include a rigidrod portion extending from one end of the insert for forming a rigidconstruct between two or more vertebrae.

FIG. 21 is a cross-sectional view of the support construct 422 in anassembled configuration, with the medial portion 438 positioned in theU-shaped channel of the housing 14 of a pedicle screw 12 and the flanges434, 436 positioned on either side of the housing 14. In the assembledconfiguration, an end portion of the flexible cord 30 is positioned inthe bore 440 of the insert 432 and the clamping member 450 is pressedinto engagement with the cord 30 with the fastener 20.

The fastener 20 can then be engaged with the housing 14, such as throughrotational movement of the fastener 20 relative to the housing 14. Insome instances, the fastener 20 can include a threaded portion whichthreadably engages a threaded portion of the housing 14, such asinternally threaded portions of opposing legs of the housing 14 definingthe channel 15. Rotational movement of the fastener 20 moves thefastener 20 into engagement with the clamping member 450.

Although not shown, the rigid rod member 470 can extend to one or moreadditional pedicle screws which can be secured to correspondingvertebrae of the spinal column. Furthermore, the cord 30 can extend inan opposite direction from the insert 432 to one or more additionalpedicle screws which can be secured to vertebrae of the spinal column.Furthermore, a spacer 24, such as that shown in FIG. 20, can bepositioned between the flange 434 and another insert 432 and/or pediclescrew with the flexible cord 30 extending through the spacer 24, toprovide a flexible construct at one or more vertebral levels.

Another spinal fixation system 510 for stabilizing a portion of a spinalcolumn, such as one or more spinal segments of a spinal column is shownin FIG. 22. The spinal stabilization system 510 can include one or moreor a plurality of vertebral anchors, depicted as pedicle screws 12,configured to be secured to a vertebra of a spinal column. The pediclescrews 12 can include a housing 14 and a shaft 16, which can includethreads, extending from the housing 14. The pedicle screws 12 can bepoly-axial, mono-axial or mono-planar, if desired. As shown in thecross-sectional view of FIG. 23A, the pedicle screws 12 can becannulated (e.g., the threaded shaft 16 can having a central lumenextending longitudinally therethrough) to be delivered to the anatomyover a K-wire 590.

The pedicle screw 12 can include a securing element, such as a threadedfastener 520 (e.g., a set screw, cap) configured to rotatably engage thehousing 14 to secure a portion of a support construct 522 to the pediclescrew 12. The fastener 520 can be rotatably engaged between spaced apartlegs of the housing 14 which define a channel of the housing 14therebetween. The fastener 520 can also be cannulated to be advanced tothe housing 14 of the pedicle screw along a K-wire 590

The spinal stabilization system 510 can also include one or more, or aplurality of support constructs 522 extending between pedicle screws 12of the spinal stabilization system 510. The support construct 522 can beconstructed of a plurality of components in some instances. Forinstance, the support construct 522 can include spacers 24, and aplurality of flexible members such as a first flexible cord 530 a and asecond flexible cord 530 b extending through the spacers 24, as well asother components if desired. The cords 530 a, 530 b can extend from thehousing 14 of the first pedicle screw 12 to the housing 14 of the secondpedicle screw 12.

In some embodiments, the spacers 24 can have a lumen extending from afirst end to a second end of the spacer 24, as shown in FIG. 23A, forreceiving the first and second flexible cords 530 a, 530 b therethrough.In other instances, the spacers 24 can include a plurality of lumensextending therethrough, each configured to receive a separate one of theplurality of flexible cords, for example. For instance, the spacer caninclude a first lumen configured to receive the first flexible cord 530a and a second lumen configured to receive the second flexible cord 530b, maintaining the first and second flexible cords 530 a, 530 b isolatedfrom one another through the spacer 24.

When implanted in a patient, the cords 530 a, 530 b of the spinalstabilization system 510 can limit the range of flexion of the spinalsegment, whereas the spacers 24 can limit the range of extension of thespinal segment. For instance, the cords 530 a, 530 b can be placed intension and the spacers 24 can be placed in compression between thepedicle screws 12.

The spinal stabilization system 510 can also include inserts 532configured to be inserted into the channels of the housings 14 of thepedicle screws 12. The insert 532 is further illustrated in FIGS. 24-26.The inserts 532, which can be considered spools in some instances, caninclude a first flange 534 proximate a first end of the insert 532, asecond flange 536 proximate the second end of the insert 532, and amedial portion 538 intermediate the first flange 534 and the secondflange 536 and extending therebetween. The insert 532 can have endsurfaces 548 configured to abut an end surface of the spacers 24. Forinstance, when assembled an end surface 548 of an insert 532 coupledwith the first pedicle screw 12 can abut an end surface of the spacer 24proximate the first end of the spacer 24 and an end surface 548 of aninsert 532 coupled with the second pedicle screw 12 can abut an endsurface of the spacer 24 proximate the second end of the spacer 24.

The insert 532 can be configured such that the medial portion 538 ispositionable in the channel of the housing 14 of the pedicle screw 12with the first flange 534 positioned exterior of the housing 14 andfacing the first side of the housing 14 and the second flange 536positioned exterior of the housing 14 and facing the second side of thehousing 14.

The insert 532 can include a plurality of bores extending therethrough,such as a first bore 540 a and a second bore 540 b, each extending froma first end surface 548 at the first end of the insert 532 to a secondend surface 548 at the second end of the insert 532. As shown in FIG.26, the first bore 540 a can extend generally parallel to and spacedapart from the second bore 540 b. Each of the bores 540 a, 54 b can beconfigured to receive one of the cords 530 a, 530 b therein. Forinstance, the first cord 530 a can be inserted into and/or through thefirst bore 540 a of the insert 532 and the second cord 530 b can beinserted into and/or through the second bore 540 b of the insert 532.

The insert 532 can include an opening 542 in the medial portion 538 ofthe insert 532 for receiving a clamping member to bear against the cords530 a, 530 b. As shown in FIG. 25, the opening 542 can intersect witheach of the first and second bores 540 a, 540 b to provide directengagement of the clamping member with a portion of each of the firstand second cords 530 a, 530 b positioned in the bores 540 a, 540 b,respectively. In some instances, the insert 532 can include a lowerportion 543 of the opening 542 extending below the first and secondbores 540 a, 540 b such that the opening 542 extends entirely throughthe insert 532 from an upper surface to a lower surface of the medialportion 538 to accommodate the K-wire 590 extending through the opening542 of the insert 532, as shown in FIG. 23A. In some instances, theinsert 532 can be positioned in the channel of the housing 14 of thepedicle screw 12 with the first and second cords 530 a, 530 b extendingthrough the first and second bores 540 a, 540 b of the insert 532 byadvancing the insert 532 along the K-wire 590 (i.e., with the K-wire 590extending through the opening 542) while the K-wire 590 is positionedthrough the longitudinal lumen extending through the shaft 16 of thepedicle screw 12 and the opening 542 through the insert 532. The K-wire590 can extend through the opening 542 of the insert 532 with the K-wire590 positioned between the first and second cords 530 a, 530 b. Thus,the longitudinal lumen extending through the shaft 16 of the pediclescrew 12 and the opening 542 through the insert 532 can be coaxiallyaligned, in some instances.

The clamping member can be a fastener 520, such as a threaded set screwincluding threads which mate with threads formed in the housing 14. Thefastener 520 can be rotatably engaged between spaced apart legs of thehousing 14 to apply a clamping force to the first and second cords 530a, 530 b to clamp or secure the cords 530 a, 530 b within the first andsecond bores 540 a, 540 b of the insert 532 while simultaneouslyclamping the insert 532 in the housing 14 of a pedicle screw 12. Forexample, as shown in FIGS. 23B and 27, the fastener 520 can include athreaded portion 226 and a protuberance 224 extending from the threadedportion 226. As shown in FIG. 27, the protuberance 224 can extend intothe opening 542 to bear against each of the first and second cords 530a, 530 b and simultaneously clamp the first and second cords 530 a, 530b in the first and second bores 540 a, 540 b, respectively. In someinstances, the cords 530 a, 530 b can be clamped in the insert 532 withthe fastener 520 while the K-wire 590 is positioned through thelongitudinal lumen extending through the shaft 16 of the pedicle screw12, the opening 542 through the insert 532, and the opening 528 throughthe fastener 520. Thus, the longitudinal lumen extending through theshaft 16 of the pedicle screw 12, the opening 542 through the insert532, and the opening 528 through the fastener 520 can be coaxiallyaligned, in some instances.

Those skilled in the art will recognize that the present invention maybe manifested in a variety of forms other than the specific embodimentsdescribed and contemplated herein. Accordingly, departure in form anddetail may be made without departing from the scope and spirit of thepresent invention as described in the appended claims.

1. A spinal stabilization system comprising: an insert positionable in achannel of a housing of a vertebral anchor, the insert having a firstend positionable on a first side of the housing of the vertebral anchorand a second end positionable on a second side of the housing of thevertebral anchor; and a support construct including a spacer and firstand second cords extendable through the spacer, the first and secondcords positionable through the insert.
 2. The spinal stabilizationsystem of claim 1, wherein the insert includes a first bore forreceiving the first cord therethrough and a second bore for receivingthe second cord therethrough.
 3. The spinal stabilization system ofclaim 1, further comprising: a vertebral anchor including a housingdefining a channel; and a fastener configured to rotatably engage thehousing of the vertebral anchor, wherein rotational engagement of thefastener with the housing causes the fastener clamp both the first andsecond cords in the insert.
 4. The spinal stabilization system of claim3, wherein the fastener directly contacts each of the first and secondcords to exert a clamping force directly on the first and second cords.5. The spinal stabilization system of claim 3, wherein the fastenerincludes a threaded portion and a protuberance extending from thethreaded portion, wherein the protuberance is extendable into an openingof the insert to contact each of the first and second cords.
 6. Thespinal stabilization system of claim 5, wherein the opening intersectswith each of the first and second bores.
 7. The spinal stabilizationsystem of any one of claim 3, wherein rotational engagement of thefastener with the housing causes the fastener to clamp both the firstand second cords in the insert and secure the insert in the housing ofthe vertebral anchor.
 8. The spinal stabilization system of claim 7,wherein the first bore extends parallel to and offset from the secondbore, and the opening extends perpendicular to and between the first andsecond bores.
 9. The spinal stabilization system of any one of claim 3,wherein the vertebral anchor includes a threaded shaft extending fromthe housing, wherein the threaded shaft has a lumen extendingtherethrough for advancement over a K-wire.
 10. The spinal stabilizationsystem of claim 9, wherein the opening extends entirely through theinsert such that the insert is advanceable over the K-wire into thehousing of the vertebral anchor with the K-wire positionable between thefirst and second cords.
 11. A spinal stabilization system comprising: aninsert securable to a housing of a vertebral anchor, the insert having afirst flange positionable on a first side of the housing of thevertebral anchor, a second flange positionable on a second side of thehousing of the vertebral anchor, and a medial portion between the firstand second flanges positionable in a channel of the housing of thevertebral anchor; and a support construct including a spacer and a cordextendable through the spacer, the cord positionable through a bore ofthe insert; a clamping member movable relative to the medial portion toclamp the cord in the bore of the insert.
 12. The spinal stabilizationsystem of claim 11, wherein the clamping member includes a concaveengagement surface configured to press against a portion of theperiphery of the cord, preferably 30 degrees or more of the periphery ofthe cord.
 13. The spinal stabilization system of claim 11, wherein theclamping member includes a first tab movable in a channel in the firstflange and a second tab movable in a channel in the second flange. 14.The spinal stabilization system of claim 13, wherein the clamping memberis configured to be held in a loading position prior to clamping ontothe cord.
 15. The spinal stabilization system of claim 13, wherein eachof the channels has an upper portion having a first width and a lowerportion having a second width, the first width being less than the widthof the first and second tabs to form an interference fit with the firstand second tabs, and the second width being greater than the width ofthe first and second tabs.
 16. The spinal stabilization system of claim13, wherein each of the channels has an upper portion having a firstwidth and a lower portion having a second width, wherein the first widthand the second width are equal.
 17. The spinal stabilization system ofclaim 13, wherein each of the channels has an upper portion having aprotuberance extending radially towards the bore, wherein each of thefirst tab and the second tab have a void disposed therein to matinglyreceive the respective protuberance.